Republican presidential front-runner Donald Trump is retaining his edge in the 2016 GOP race, but his advantage has dropped from 16 points over Sen. Ted Cruz of Texas to 9 points in a new national poll.

Mr. Trump had the support of 34 percent of registered Republicans and GOP-leaning independents in the Washington Post-ABC News poll out Tuesday, followed by Mr. Cruz at 25 percent, Sen. Marco Rubio of Florida at 18 percent and Ohio Gov. John Kasich at 13 percent.

In January, Mr. Trump had been at 37 percent, followed by Mr. Cruz at 21 percent, Mr. Rubio at 11 percent and Mr. Kasich at 2 percent.

Mr. Trump also lost a head-to-head match-up to Mr. Cruz by 13 points, 54 percent to 41 percent, and trailed Mr. Rubio by 6 points, 51 percent to 45 percent.

Fifty-one percent said they would be satisfied with Mr. Trump as the GOP nominee, compared to 65 percent who said the same of Mr. Cruz, 62 percent for Mr. Rubio, and 56 percent for Mr. Kasich.

And 53 percent gave Mr. Trump a favorable rating, compared to 46 percent who reported an unfavorable view. That’s down from a 60 percent/39 percent favorable/unfavorable split in January.

Sixty-four percent reported positive views of Mr. Cruz and 63 percent said the same of Mr. Rubio.

Among all adults, 67 percent said they have an unfavorable view of Mr. Trump, compared to 30 percent with a favorable view. Fifty-one percent of adults had an unfavorable view of Mr. Cruz and 45 percent had an unfavorable view of Mr. Rubio.

On the Democratic side, former Secretary of State Hillary Clinton led Sen. Bernard Sanders of Vermont by 7 points, 49 percent to 42 percent. That’s down from a 19-point, 55 percent to 36 percent, advantage for Mrs. Clinton in January.